But the growing tensions between them, conflict in the Middle East and alarming threat of North Korea has led to increased development of nuclear warheads. "World leaders must now take the right step and sign the Treaty on the Prohibition of Nuclear Weapons that opened for signatures at the United Nations on September 20, 2017".
According to SIPRI data, Russian Federation has 7,000 nuclear weapons while the United States follows closely with 6,800.
China foreign ministry says USA should focus on promoting regional stability instead of diversifying its nuclear arsenal.
According to the Congressional Budget Office, the new American nuclear programs could cost as much as $1.2 trillion. The U.S. says it has been in compliance with the limits since August and it expects the Russians to comply by the deadline.
A red danger tag hanging in the command and control center is seen inside U.S. Virginia-class nuclear attack submarine USS Hawaii at the U.S. naval base in Yokosuka, south of Tokyo, Aug. 22, 2014.
Washington also "arbitrarily converted" some underground missile launch sites into training facilities, which wasn't spelled out in the treaty, the ministry said.
John Burroughs, executive director of the New York-based Lawyers Committee on Nuclear Policy, said the NPR ignores worldwide legal obligations of the United States and increases the risks of nuclear war.
The New START treaty, the State Department said, is "critically important at a time when trust in the relationship has deteriorated and the threat of miscalculation and misperception has risen".
The 2018 Nuclear Posture Review (NPR), released February 2, is a unsafe departure from the past, and appears to reflect a firm US commitment to readily use the world's deadliest weapons of mass destruction - even if the United States is only a target of "significant non-nuclear strategic attacks", including cyberattacks.
While the document underscored the administration's concerns about North Korea, Iran and China, the focus fell largely on Russian Federation.
"The idea is, once again, to keep our negotiators negotiating from a position of strength", Mattis told a House Armed Services Committee hearing on the administration's Nuclear Posture Review, which was released last week.
The statement came as a reaction to the Pentagon's released Nuclear Posture Review that discussed the United States military outlook on nuclear threats.
The Pentagon-led review of the US nuclear arsenal and the policies that govern it was ordered by Trump a year ago.
"This change runs directly counter to an NPT commitment to reduce the role of nuclear weapons in security policies in order to facilitate disarmament".
The United States and Russian Federation signed The Strategic Arms Reduction Treaty (New START) in 2010 that requires both the countries to limit their nuclear weapons to 1,550 each.
"There is no scenario in which the Kim regime could employ nuclear weapons and survive", it says.
Rouhani, who opened the way to Tehran's 2015 nuclear deal with world powers including the United States, added: "The same people who supposedly believe that using weapons of mass destruction is a crime against humanity ... are talking about new weapons to threaten or use against rivals".
The Pentagon's nuclear review concluded that while arms control can advance American interests, "further progress is hard to envision", in light of what the USA considers Russia's aggression in Ukraine and violations of existing arms deals.
Rachel Bronson, CEO and president of the Bulletin of the Atomic Scientists, said the Nuclear Posture Review "is a spruced-up Cold War document, responding in dated ways to current threats".